Objective: To establish a method for determining the molecular weight and molecular weight distribution of Poly(Lactide-co-Glycolide Acid) (PLGA) using Size Exclusion Chromatography-Refractive Index-Multiangle Laser Light Scattering (SEC-RI-MALLS) and Size Exclusion Chromatography-Refractive Index (SEC-RID), and to compare the results obtained from these two methods.
Methods: For SEC-RI-MALLS, tetrahydrofuran was used as the mobile phase, Shodex GPC KF-803L was employed as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, and an injection volume of 100 μL. For SEC-RID, tetrahydrofuran was also used as the mobile phase, Agilent PLgel 5 μm MIXD-D was used as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, differential detector temperature at 35 ℃, and an injection volume of 20 μL. The molecular weight and molecular weight distribution were calculated using Agilent’s GPC software. The newly established methods were validated methodologically, and the molecular weight and molecular weight distribution of 13 batches of samples were determined.
Results: The precision, accuracy, stability, and repeatability tests for SEC-RI-MALLS showed RSD values of 1.35%, 1.58%, 1.53%, and 1.26%, respectively. The SEC-RID method exhibited good linearity (r=0.999 9), with RSD values for precision, accuracy, stability, and repeatability tests (n=6) of 2.05%, 1.62%, 1.30%, and 2.97%, respectively. The results obtained from SEC-RI-MALLS were lower than those from SEC-RID, and the molecular weight distribution coefficient was smaller, but the results from the paired T-test performed with the value measured by SEC-RID method and the value measured by SEC-RI-MALLS method multiplied a conversion coefficient of 1.5 showed no significant difference between the two methods.
Conclusion: Both methods are stable and reliable, and can be used for the determination of PLGA molecular weight and molecular weight distribution based on the specific situations.

Objective: To analyze the change trends in the body shape indicators and proportions of students in Harbin from 2010 to 2024, and to investigate ergonomic compatibility of functional dimensions of school desks and chairs with current student shape indicators, so as to provide a reference for revising furniture standards of desks and chairs. Methods: Between September and November of both 2010 and 2024, a combination of convenience sampling and stratified cluster random sampling was conducted across three districts in Harbin, yielding samples of 6 590 and 6 252 students, respectively. Anthropometric shape indicators cluding height, sitting height, crus length, and thigh length-and their proportional changes were compared over the 15-year period. The 2024 data were compared with current standard functional dimensions of school furniture. The statistical analysis incorporated t-test and Mann-Whitney U- test. Results: From 2010 to 2024, average height increased by 1.8 cm for boys and 1.5 cm for girls; sitting height increased by 1.5 cm for both genders; crus length increased by 0.3 cm for boys and 0.4 cm for girls; and thigh length increased by 0.5 cm for both genders. The ratios of sitting height to height, and sitting height to leg length increased by less than 0.1 . The difference between desk chair height and 1/3 sitting height ranged from 0.4-0.8 cm. Among students matched with size 0 desks and chairs, 22.0% had a desk to chair height difference less than 0, indicating that the desk to chair height difference might be insufficient for taller students. The differences between seat height and fibular height ranged from -1.4 to 1.1 cm; and the differences between seat depth and buttock popliteal length ranged from -9.8 to 3.4 cm. Among obese students, the differences between seat width and 1/2 hip circumference ranged from -20.5 to -8.7 cm, while it ranged from -12.2 to -3.8 cm among non obese students. Conclusion Current furniture standards basically satisfy hygienic requirements; however, in the case of exceptionally tall and obese students, ergonomic accommodations such as adaptive seating allocation or personalized adjustments are recommended to meet hygienic requirements.

To explore the inhibitory effect of ginkgolide B (GB) on MH7A human fibroblast-like synoviocytes (FLS) and its potential mechanism. Firstly, 20 μg/L tumor necrosis factor-α (TNF-α) was pretreated with MH7A to establish a cell model of arthritis. After incubation of MH7A cells with various concentrations of GB, CCK-8 assay, Transwell assay, and flow cytometry (FCM) were separately used to detect cell viability, cell invasion, and cell apoptosis rate and cell cycle; Real-time quantitative PCR and Western blot assay were performed to detect the apoptosis- and cycle-related gene transcriptions and protein expressions, respectively. The results showed that compared with the control group, GB dose- and time-dependently suppressed cell viability to a greater extent; GB significantly reduced cell invasive ability and increased cell apoptosis rate and proportion of G0/G1 phase in MH7A cells, along with increased transcription levels of Bcl-2-associated X protein (Bax) and p21 mRNA and decreased transcription levels of Bcl-2, myeloid cell leukemia 1(Mcl-1), protein kinase B (PKB; AKT), IP3K, Cyclin D1 and cyclin-dependent kinase 4 (CDK4) mRNA; GB remarkably increased expression levels of Bax, p21, and cleaved-Caspase 3 protein and decreased expression levels of Bcl-2, Mcl-1, p-AKT, p-PI3K, Cyclin D1, and CDK4 protein, with decreased ratios of p-PI3K/PI3K, p-AKT/AKT, and Bcl-2/Bax. In conclusion, GB blocks the G1-to-S cell cycle transition, suppresses cell viability and cell invasion and induces cell apoptosis of MH7A human RA-FLS via suppressing the PI3K/AKT signaling pathway.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To systematically search,evaluate and summarize the best evidence for prevention and management of extravasation in peripheral intravenous infusion in NICU neonates,and provide a reference for clinical practice and standard formulation.Methods A comprehensive systematic search of websites and databases was conducted to explore literature on prevention and management of extravasation in NICU neonates,including clinical decisions,guidelines,expert consensuses,evidence summaries and systematic reviews.The search encompassed the entire period from database inception to July 2023.2 researchers independently evaluated the quality of the literature,extracted and integrated the evidence.Results The study included a total of 9 articles,comprising 1 clinical decision,3 guidelines,3 expert consensus documents,and 2 evidence summaries.Ultimately,25 pieces of evidence were synthesized,covering risk factors,catheter indwelling and maintenance,extravasation assessment and treatment,and team building,education and training.Conclusion The evidence provided practical and specific recommendations that can guide healthcare institutions in formulating strategies to prevent and treat extravasation during peripheral intravenous infusion in NICU neonates,while also offering evidence-based guidance for applying the evidence in clinical practice.

Objective To analyze the predictive value of serum solitary G protein-coupled receptor ligand-12(Apelin-12)combined with echocardiographic parameters,wall motion score(WMS)and left ventricular global longitudinal strain(LV-GLS)for heart failure(HF)in elderly patients with acute myocardial infarction(AMI)after percutaneous coronary intervention(PCI).Methods A total of 98 elderly AMI patients undergoing PCI in our hospital from January 2021 to December 2023 were enrolled,and according to the occurrence of HF or not at 3 months after PCI,they were divided into HF group(39 cases)and non-HF group(59 cases).PCI procedure was completed within 12 h after admission,and the blood samples were collected and echocardiography was per-formed at discharge.ROC curve was plotted to evaluate the predictive value of Apelin-12,WMS and LV-GLS for HF in elderly AMI patients.Kappa consistency test was conducted to assess the accuracy of combined the three indicators in predicting HF in the patients.Results The HF group had significantly lower serum Apelin-12 level,and higher WMS and LV-GLS than the non-HF group(P＜0.01).ROC curve analysis showed that the AUC value of Apelin-12,WMS and LV-GLS in predicting HF after PCI in elderly AMI patients was 0.931,0.745 and 0.749,respec-tively,and their cut-off values was 1.55 μg/L,20.50 and-12.90％,respectively.Multivariate lo-gistic regression analysis revealed that serum Apelin-12＜1.55 μ g/L,WMS＞20.50 points,and LV-GLS＞-12.90％were independent risk factors for postoperative HF in elderly AMI patients(OR=3.508,95％CI:2.002-6.147);OR=2.818,95％CI:1.479-5.371;OR=2.841,95％CI:1.505-5.363).When the three indicators combined in tandem,that is,when serum Apelin-12＜1.55 μg/L,WMS＞20.50 and LV-GLS＞-12.90％,HF was predicted to be positive,with a speci-ficity increasing to 94.92％and a Kappa value of 0.714(P＜0.01).Conclusion Detection of serum Apelin-12,WMS and LV-GLS is beneficial for elderly AMI patients after PCI in predicting the oc-currence of HF,and can open up a new direction for clinical diagnosis and treatment.

Objective:To investigate the changes in interaction proteome of NUS1 mutant R290C and their relations with pathogenicity of Lennox Gastaut syndrome (LGS). Methods:The wild-type and mutant NUS1(R290C) plasmids were constructed and transfected into human embryonic kidney HEK293T cells; 48 h after that, NUS1 protein expression in HEK293T cells was detected by Western blotting. Co-immunoprecipitation, silver nitrate staining, and proteomic analysis were used to analyze the proteins interacted with wild-type or mutant NUS1 and identify the differential interacting proteins. Enrichment analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed to annotate the molecular function and signaling pathways involved in the differential proteins. DisGeNet database was used to analyze the association between differential proteins and human diseases. Protein-protein interaction (PPI) was used to analyze the interaction network of NUS1 with protein folding regulatory proteins (RTN4 and DHDDS) and developmental epileptic encephalopathy related proteins.Results:(1) There was no significant difference in NUS1 protein expression between the wild-type and mutant NUS1 transfected HEK293T cells ( t=0.536, P=0.620). (2) Compared with that with wild-type NUS1 plasmid, number of proteins interacting with mutant NUS1 plasmid was significantly reduced in the transfected cells; 310 differential interacting proteins were screened in the mutant NUS1. (3) GO and KEGG enrichment analyses showed that the differential proteins were mainly involved in protein folding reaction and translation regulation. (4) DisGeNet association analysis showed that the two most relevant proteins in the differential interacting proteins were associated with frontotemporal dementia and developmental epileptic encephalopathy. (5) PPI analysis showed that NUS1 may be involved in occurrence of neurological diseases such as LGS by affecting protein folding signaling pathways. Conclusion:NUS1 mutant R290C alters its interacting protein lineage and mediates the development of LGS and other neurological diseases probably by regulating protein folding-related signaling.

The early diagnosis of congenital heart disease is very important. Ultrasound is widely used in the early diagnosis and evaluation of congenital heart disease because of its advantages of non-radiation, non-invasive property and portability.Speckle tracking imaging has the advantages of being free from angle, efficient and accurate, which makes up for some shortcomings of traditional echocardiography. It greatly improves the diagnosis accuracy of fetal congenital heart disease, especially congenital heart disease with outflow tract obstruction.Myocardial strain index and left ventricular torsion can more accurately evaluate myocardial function,help to judge prognosis, choose the time of operation and assist perioperative management. Blood speck tracking helps identify different blood flow patterns and may become an important diagnostic tool for the diagnosis and treatment of congenital heart disease.

The comprehensive detection and identification of active ingredients in complex matrices is a crucial challenge.Liquid chromatography coupled with high-resolution mass spectrometry(LC-HRMS)is the most prominent analytical platform for the exploration of novel active compounds from complex matrices.However,the LC-HRMS-based analysis workflow suffers from several bottleneck issues,such as trace content of target compounds,limited acquisition for fragment information,and uncertainty in interpreting relevant MS2 spectra.Lycibarbarspermidines are vital antioxidant active ingredients in Lycii Fructus,while the reported structures are merely focused on dicaffeoylspermidines due to their low content.To comprehensively detect the new structures of lycibarbarspermidine derivatives,a"depict"strategy was developed in this study.First,potential new lycibarbarspermidine derivatives were designed according to the biosynthetic pathway,and a comprehensive database was established,which enlarged the coverage of lycibarbarspermidine derivatives.Second,the polarity-oriented sample prep-aration of potential new compounds increased the concentration of the target compounds.Third,the construction of the molecular network based on the fragmentation pathway of lycibarbarspermidine derivatives broadened the comprehensiveness of identification.Finally,the weak response signals were captured by data-dependent scanning(DDA)followed by parallel reaction monitoring(PRM),and the efficiency of acquiring MS2 fragment ions of target compounds was significantly improved.Based on the integrated strategy above,210 lycibarbarspermidine derivatives were detected and identified from Lycii Fructus,and in particular,170 potential new compounds were structurally characterized.The integrated strategy improved the sensitivity of detection and the coverage of low-response components,and it is expected to be a promising pipeline for discovering new compounds.

Purpose: Vaccinia virus is widely used as an oncolytic agent for human cancer therapy, and several versions of vaccinia virus have demonstrated robust antitumor effects in breast cancer. Most vaccinia viruses are modified by thymidine kinase (TK) deletion. The function of the cyclin-dependent kinase inhibitor p21 in breast cancer remains controversial. We explored the impact of p21 gene knockdown (KD) on breast cancer cells and whether p21 KD interferes with the antitumor effect of TK-negative vaccinia virus. Methods: p21 KD MDA-MB-231 and p21 KD MCF-7 cells were prepared, and cell proliferation and migration rates were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch healing assays. The tumor growth of xenografts originating from p21KD MDA-MB-231 cells and control cells was compared in a mouse model. The colony formation and sphere-forming abilities of p21 KD breast cancer cells were also determined using low-melting agarose and serum-free culture. The tumorkilling effect of the vaccinia virus was determined in breast cancer cells and mouse models using an MTT assay and tumor cell xenografts. Results: p21 KD increased the growth and migration of MDA-MB-231 and MCF-7 cells and promoted the cell growth of MDA-MB-231 cells in mice, while decreasing the colony formation and sphere formation abilities. Expression of TK was reduced in p21 KD MDAMB-231 cells. Oncolytic effects of both wild-type and TK-deleted vaccinia viruses were attenuated in p21KD MDA-MB-231 cells. The tumor-killing effect of TK-deleted vaccinia virus was also weakened in xenografted mice bearing p21 KD MDA-MB-231 cells. Conclusion Targeted inhibition of p21 accelerates the proliferation and migration of breast cancer cells and impairs the tumor-killing effect of vaccinia virus, suggesting that p21 levels in cancer cells interfere with vaccinia virus oncolytic therapy.